An automatic power supply test system is used to test the performance of a power supply. These test systems automatically measure the parameters such as input voltage, current, power, power factor, output voltage, current, ripple and noise, short-circuit protection, over-voltage protection (OVP) and over-current protection (OCP) of a power supply. An automatic power supply test system is often used in power supply production line to ensure products meet the specifications before they are packed for shipment. An automatic power supply test system usually consists of a central computer with application software to control an automatic power source, a power analyzer, an electronic load, a multi-channel DC voltage/current meter, a ripple/noise measurement device and some special circuitry to tests the protection functions. Furthermore, an automatic power supply test system needs to be user programmable so it can be used to test power supplies of various types and power ratings.
FIG. 1 is the block diagram of a typical automatic power supply test system existing today. The system has an industrial PC as the central computer. The PC communicates to various system components via a standard communication bus, such as IEEE488 bus. From the PC, a user can edit the test requirement through the application software. For instance, if the user wants to test the efficiency of a power supply, he/she would, through the application software, set the Automatic Power Source 12 to the nominal input voltage of that power supply, set the electronic load 16 to draw the rated output current of that power supply, set the Power Analyzer 13 to measure the input power of the power supply, and set the Precision DC meters 15 to measure the output voltage and current of the power supply. He/she also needs to setup the application software to calculate the efficiency using the collected measurement results and output the efficiency to a desired file and in desired format.
While this conventional architecture has the flexibility to allow the user to program each system components freely, its drawback is the relatively high cost. First, to communicate with the PC through IEEE488 bus, every system component needs to have the IEEE488 interface circuitry. Second, the various system components are often standard equipment that has human interface and other features that are not necessary for the automatic test system.
The main objective of the current invention is to achieve lower cost system architecture for the same test functionality. Another objective of the current invention is to have two or more test units operating at the same time, controlled by the same PC, sharing the same programmable power source and operated by a single operator in a power supply production line. This allows higher throughput and better work efficiency for the production line.